Electronic control units (ECUs) for various functions are mounted throughout a system, such as working machinery (a combine harvester, a tiller, etc.) and a ship (a pleasure boat, a fishing boat, etc.), in order to control the functions.
A combine harvester (or simply combine), as an example of such a system, has various functions including threshing, travel control, reaping, engine actuation, and metering and is provided with one or more electronic control units each controlling at least one of these functions. If two or more electronic control units are provided, some functions may be covered by more than one electronic control unit. Specifically, threshing functions may be controlled by three electronic control units: a first one primarily for the control of functions after the threshing, a second one primarily for the control of functions during the threshing, and the last one primarily for the control of functions of the whole combine harvester. Travel control functions may be controlled by three electronic control units: a first one primarily for the control of functions after the threshing, a second one primarily for the control of functions of the whole combine harvester, and the last one primarily for the control of reaping functions. Reaping functions may be controlled by two electronic control units: a first one primarily for the control of functions of the whole combine harvester and the other one primarily for the control of reaping functions.
In addition, each electronic control unit is adapted to, as necessary, record and store history record information (e.g., history and accumulated information) on function data about various functions, for example, input signals (detection signals) obtained from various sensors, output signals (actuation signals) fed to various actuators, such as electromagnetic valves, and measurement signals obtained from measuring instruments.
A system equipped with these electronic control units may be connected to a data collecting device via a USB (universal serial bus) port or other interface. The data collecting device may be, for example, a laptop or like mobile personal computer with a data collecting program.
The data collecting device, once connected to the system, collects function data stored in the electronic control units in the system to aggregate and analyze the function data or to diagnose errors.
Conventionally, when a data collecting device is connected to the system to collect function data about various functions as above, the data collecting device communicates, for each function, with all electronic control units in the system to check presence/absence of the function before collecting function data about the function. This way of collecting function data is disadvantageously time-consuming.
Especially, when function data needs to be collected about a plurality of functions, the time taken to collect function data increases with the number of functions about which function data is to be collected because, for each function, the data collecting device needs to communicate with all electronic control units to check presence/absence of that function and subsequently collect and process function data about the function until this process is repeated for all the functions.
The process will be described more specifically in reference to FIG. 18 which is a system configuration diagram schematically illustrating a conventional data collecting device Y which, connected to a system X, collects history record information on function data Da to Di about various functions A to I.
The system X shown in FIG. 18 is adapted to be connected to the data collecting device Y via a USB port or other interface Z.
The system X includes a first electronic control unit ECU1 controlling functions A and B, a second electronic control unit ECU2 controlling functions B and C, a third electronic control unit ECU3 controlling functions C and D, a fourth electronic control unit ECU4 controlling functions D and E, a fifth electronic control unit ECU5 controlling functions E and F, a sixth electronic control unit ECU6 controlling functions F and G, a seventh electronic control unit ECU7 controlling functions G and H, and an eighth electronic control unit ECU8 controlling functions H and I.
The first to eighth electronic control units ECU1 to ECU8 are connected to each other over a network N, such as a CAN (controller area network) acting as an in-vehicle LAN (local area network), for two-way data communications.
The first electronic control unit ECU1 stores history record information on function data Da and Db about functions A and B. Likewise, the second to eighth electronic control units ECU2 to ECU8 respectively store history record information on function data Db and Dc about functions B and C, history record information on function data Dc and Dd about functions C and D, history record information on function data Dd and De about functions D and E, history record information on function data De and Df about functions E and F, history record information on function data Df and Dg about functions F and G, history record information on function data Dg and Dh about functions G and H, and history record information on function data Dh and Di about functions H and I.
For at least one of functions A to I, the data collecting device Y communicates with all the electronic control units ECU1 to ECU8 in the system X to check presence/absence of the function(s) before collecting history record information on function data about the function(s).
For example, to collect history record information on function data Da, Dc, and De about functions A, C, and E, the data collecting device Y first asks the first electronic control unit ECU1 whether it controls function A, i.e., whether it possesses function data Da about function A. Since the first electronic control unit ECU1 possesses function data Da about function A, the first electronic control unit ECU1 returns to the data collecting device Y a message that it possesses function data Da about function A. The data collecting device Y recognizes that the first electronic control unit ECU1 possesses function data Da about function A and collects history record information on function data Da about function A from the first electronic control unit ECU1. Next, the data collecting device Y asks the second electronic control unit ECU2 whether it possesses function data Da about function A. Since the second electronic control unit ECU2 does not possess function data Da about function A, the second electronic control unit ECU2 returns to the data collecting device Y a message that it does not possess function data Da about function A. Subsequently, the same procedures are repeated with the third to eighth electronic control units ECU3 to ECU8. After that, the whole process described so far is performed on function C and then function E as well.
The data collecting device Y communicates with the first to eighth electronic control units ECU1 to ECU8 sequentially for each of functions A, C, and E as detailed above. Therefore, the time taken to collect function data increases with the number of functions about which function data is to be collected and the number of electronic control units.
This problem is addressed by Patent Document 1 (for example, paragraphs [0034] and [0035]) which discloses a configuration in which a system including a plurality of electronic control units (ECUs) is provided in advance with a system-type table containing various data for each system type to facilitate data collection from the system.